It sounds like you're looking for a templating system. HTML::Template will allow you to set up templates that are completed via Perl. You can even use HTML::Template to "include" templates from other files. That allows you to set up a framework template, a header template, a footer template, and so on, just pulling them all together as appropriate.

Eventually you may want to look at a more full featured framework such as Mojolicious (probably starting with a Mojolicious::Lite application). That provides templating, and a whole lot more. It helps to promote a separation of concerns (Model / View / Controller), which has become a fairly standard way of doing things, and certainly a "best practice."

When putting a smiley right before a closing parenthesis, do you:

Use two parentheses: (Like this: :) )
Use one parenthesis: (Like this: :)
Reverse direction of the smiley: (Like this: (: )
Use angle/square brackets instead of parentheses
Use C-style commenting to set the smiley off from the closing parenthesis
Make the smiley a dunce: (:>
I disapprove of emoticons
Other